The disclosure relates generally to robots and more particularly to a jumping robot.
Many robots with jumping ability are known. For these traditional designs, jumping is accomplished by an instant release of the energy stored in the robot. As a result, all the robots with jumping ability can be classified by their energy storage methods. The most popular conventional method to store the energy is based on traditional springs such as compression, extension, or torsion springs. One exemplary jumping robot uses a motor-driven ball screw to charge and release a compression spring. In another example, the energy in an extension spring is stored and released through a geared six-bar mechanism. Yet a further example utilizes a slip gear system to store and release the energy in an extension spring via a four-bar mechanism.
Still another conventional robot employs a planetary gear train and a one-way clutch, where a conical spring directly strikes the ground. Prior prototype robots employ a motor driven eccentric cam to charge a torsion or two extension springs that actuates rear legs. A wheel-based, stair-climbing robot with soft landing ability has a jumping mechanism based on four compression springs. Another exemplary version, known as the EPFL jumper, can achieve a jumping height about 1.4 m with torsion springs charged and released by a motor driven cam system; see Kovac, M. et al., “A Miniature 7 g Jumping Robot,” Proc. IEEE Int. Conf. Robot. Autom. (2008) at 373-378. This robot was later modified to add self-recovery capability and jumping direction changing ability; see Kovac, M. et al., “Steerable Miniature Jumping Robot,” Auton. Robots, Vol. 28, No. 3 (2010) at 295-306; and Kovac, M. et al., “A Miniature Jumping Robot with Self-Recovery Capabilities,” Proc. IEEE/RSJ Int. Conf. Intell. Robots Systems (2009) at 583-588. In another construction, a multimodal robot can jump up to 1.7 m based on two symmetrical extension spring-actuated four-bar mechanisms.
A second traditional method for energy storage is based on elastic elements such as customized special springs. A scout robot employs a motor-driven winch to charge a single bending plate spring and release it to directly strike the ground for jumping. A conventional compact jumping robot utilizes an elastic strip to form closed elastica, which is actuated by two revolute joints. With two symmetrical power springs made of carbon fiber strips as legs, another conventional microbot charges its springs with dielectric elastomer actuators. In another example, known as the Jollbot, a spherical structure formed by several metal semi-circular hoops is used to store energy in the hoops by deforming its spherical shape. A similar conventional idea is utilized in a deformable robot, but the material for hoops is replaced by shape memory alloy.
A third conventional method to store energy for jumping is based on compressed air. In this method, a robot usually carries an air tank and a pneumatic cylinder. The sudden release of air in the tank will force the cylinder to extend. A traditional rescue robot and a patrol robot employ cylinder extension to strike the ground for jumping. Instead of striking the ground, the jumping ability of another traditional robot, known as a quadruped Airhopper, is accomplished by several cylinder-actuated four-bar mechanisms. With a biped structure, another exemplary robot, different from other pneumatic-based jumping robots, uses several pneumatic artificial muscles for jumping.
In addition to the preceding, there exist several other known devices. A pendulum jumping robot is based on the principle that momentum will be generated from swinging arms during human jumping. Furthermore, a jumping robot developed by the Sandia National Labs uses the energy from hydrocarbon fuels and can achieve a significant jumping height. Another robot is based on microelectromechanical (“MEMS”) technology and has a small jumping height. Finally, an additional robot uses a voice coil actuator to charge energy into an electrical capacitor instead of a mechanical structure.
It is noteworthy, however, that traditional jumping robots are either too heavy, too expensive or too large. Furthermore, most conventional robots disadvantageously require multiple actuators which quickly use considerable battery power. While such robots may be needed for space exploration, their weight and size prevent them from achieving desired jumping heights and distances.
In accordance with the present invention, a jumping robot is provided. In another aspect, a jumping robot weighs less than 50 grams, jumps at least 20 cm high and has a maximum linear dimension of 10 cm. A further aspect provides a robot that employs a single electromagnetic actuator that actuates at least two of: jumping, steering and/or self-righting. Still another aspect employs multiple jumping robots that communicate with a remote communications station and/or each other either airborne or on the ground.
The present jumping robot is advantageous over traditional devices. For example, the present jumping robot is light weight and of small size thereby allowing it to achieve long jumping distances or large jumping heights. Furthermore, the present jumping robot is multifunctional in its movements driven by a single actuator; this assists with realizing the light weight, small size and low cost while requiring minor battery power such that more than 100 jumps can be made on a single battery charge. The present jumping robot is ideally suited for mass production so many of them can be used at a natural disaster site or in a war zone to locate victims or targets, respectively. The low cost nature avoids the need for recovery of the robot after use while allowing for many robots to be employed at a single site. Moreover, the significant jumping height allows for line-of-sight and/or airborne sensing and communications over rubble and other ground obstacles. The height of the jump provides a greater sensing and communications coverage area as well. Additional advantages and features of the present invention will become apparent from the following description and appended claims, taken in conjunction with the accompanying drawings.